/usr/share/go-1.6/test/interface/ is in golang-1.6-src 1.6.1-0ubuntu1.
This file is owned by root:root, with mode 0o755.
..
/usr/share/go-1.6/test/interface/assertinline.go
/usr/share/go-1.6/test/interface/bigdata.go
/usr/share/go-1.6/test/interface/convert.go
/usr/share/go-1.6/test/interface/convert1.go
/usr/share/go-1.6/test/interface/convert2.go
/usr/share/go-1.6/test/interface/embed.go
/usr/share/go-1.6/test/interface/embed1.dir/
/usr/share/go-1.6/test/interface/embed1.dir/embed0.go
/usr/share/go-1.6/test/interface/embed1.dir/embed1.go
/usr/share/go-1.6/test/interface/embed1.go
/usr/share/go-1.6/test/interface/embed2.go
/usr/share/go-1.6/test/interface/explicit.go
/usr/share/go-1.6/test/interface/fail.go
/usr/share/go-1.6/test/interface/fake.go
/usr/share/go-1.6/test/interface/noeq.go
/usr/share/go-1.6/test/interface/pointer.go
/usr/share/go-1.6/test/interface/private.dir/
/usr/share/go-1.6/test/interface/private.dir/private1.go
/usr/share/go-1.6/test/interface/private.dir/prog.go
/usr/share/go-1.6/test/interface/private.go
/usr/share/go-1.6/test/interface/receiver.go
/usr/share/go-1.6/test/interface/receiver1.go
/usr/share/go-1.6/test/interface/recursive.go
/usr/share/go-1.6/test/interface/recursive1.dir/
/usr/share/go-1.6/test/interface/recursive1.dir/recursive1.go
/usr/share/go-1.6/test/interface/recursive1.dir/recursive2.go
/usr/share/go-1.6/test/interface/recursive1.go
/usr/share/go-1.6/test/interface/returntype.go
/usr/share/go-1.6/test/interface/struct.go